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Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens
The alternative sigma factor RpoS controls a large regulon that allows E. coli to respond to a variety of stresses. Mutations in rpoS can increase rates of nutrient acquisition at the cost of a decrease in stress resistance. These kinds of mutations evolve rapidly under certain laboratory conditions...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Genetics Society of America
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3484664/ https://www.ncbi.nlm.nih.gov/pubmed/23173085 http://dx.doi.org/10.1534/g3.112.003855 |
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author | Snyder, Emily Gordon, David M. Stoebel, Daniel M. |
author_facet | Snyder, Emily Gordon, David M. Stoebel, Daniel M. |
author_sort | Snyder, Emily |
collection | PubMed |
description | The alternative sigma factor RpoS controls a large regulon that allows E. coli to respond to a variety of stresses. Mutations in rpoS can increase rates of nutrient acquisition at the cost of a decrease in stress resistance. These kinds of mutations evolve rapidly under certain laboratory conditions where nutrient acquisition is especially challenging. The frequency of strains lacking RpoS in natural populations of E. coli is less clear. Such strains have been found at frequencies over 20% in some collections of wild isolates. However, laboratory handling can select for RpoS-null strains and may have affected some of these strain collections. Other studies have included an unknown diversity of strains or only used a phenotypic proxy as a measure of RpoS levels. We directly measured RpoS levels in a collection of E. coli that includes the full diversity of the species and that was handled in a manner to minimize the potential for laboratory evolution. We found that only 2% of strains produce no functional RpoS. Comparison of these strains in multiple labs shows that these rpoS mutations occurred in the laboratory. Earlier studies reporting much higher levels of RpoS polymorphism may reflect the storage history of the strains in laboratories rather than true frequency of such strains in natural populations. |
format | Online Article Text |
id | pubmed-3484664 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Genetics Society of America |
record_format | MEDLINE/PubMed |
spelling | pubmed-34846642012-11-21 Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens Snyder, Emily Gordon, David M. Stoebel, Daniel M. G3 (Bethesda) Investigations The alternative sigma factor RpoS controls a large regulon that allows E. coli to respond to a variety of stresses. Mutations in rpoS can increase rates of nutrient acquisition at the cost of a decrease in stress resistance. These kinds of mutations evolve rapidly under certain laboratory conditions where nutrient acquisition is especially challenging. The frequency of strains lacking RpoS in natural populations of E. coli is less clear. Such strains have been found at frequencies over 20% in some collections of wild isolates. However, laboratory handling can select for RpoS-null strains and may have affected some of these strain collections. Other studies have included an unknown diversity of strains or only used a phenotypic proxy as a measure of RpoS levels. We directly measured RpoS levels in a collection of E. coli that includes the full diversity of the species and that was handled in a manner to minimize the potential for laboratory evolution. We found that only 2% of strains produce no functional RpoS. Comparison of these strains in multiple labs shows that these rpoS mutations occurred in the laboratory. Earlier studies reporting much higher levels of RpoS polymorphism may reflect the storage history of the strains in laboratories rather than true frequency of such strains in natural populations. Genetics Society of America 2012-11-01 /pmc/articles/PMC3484664/ /pubmed/23173085 http://dx.doi.org/10.1534/g3.112.003855 Text en Copyright © 2012 Snyder et al. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution Unported License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Investigations Snyder, Emily Gordon, David M. Stoebel, Daniel M. Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens |
title | Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens |
title_full | Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens |
title_fullStr | Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens |
title_full_unstemmed | Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens |
title_short | Escherichia coli Lacking RpoS Are Rare in Natural Populations of Non-Pathogens |
title_sort | escherichia coli lacking rpos are rare in natural populations of non-pathogens |
topic | Investigations |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3484664/ https://www.ncbi.nlm.nih.gov/pubmed/23173085 http://dx.doi.org/10.1534/g3.112.003855 |
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